I have this method for shrinking down an image for a website that I'm working on:
static byte[] createSmallerImage(
BlogPhoto blogPhoto,
int newMaxWidth,
int newMaxHeight)
{
Image img;
using (MemoryStream originalImage =
new MemoryStream(blogPhoto.BlogPhotoImage))
{
img = Image.FromStream(originalImage);
}
int newWidth;
int newHeight;
byte[] arr;
if (img.Width > img.Height)
{
if (img.Width <= newMaxWidth)
{
using (MemoryStream thumbStr = new MemoryStream())
{
img.Save(thumbStr, ImageFormat.Jpeg);
img.Dispose();
arr = thumbStr.ToArray();
}
return arr;
}
newWidth = newMaxWidth;
newHeight =
(int)(((float)newWidth / (float)img.Width) * (float)img.Height);
}
else
{
if (img.Height <= newMaxHeight)
{
using (MemoryStream thumbStr = new MemoryStream())
{
img.Save(thumbStr, ImageFormat.Jpeg);
img.Dispose();
arr = thumbStr.ToArray();
}
return arr;
}
newHeight = newMaxHeight;
newWidth =
(int)(((float)newHeight / (float)img.Height) * (float)img.Width);
}
Image thumb = new Bitmap(newWidth, newHeight);
Graphics g = Graphics.FromImage(thumb);
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.SmoothingMode = SmoothingMode.HighQuality;
g.PixelOffsetMode = PixelOffsetMode.HighQuality;
g.CompositingQuality = CompositingQuality.HighQuality;
g.DrawImage(img, 0f, 0f, (float)newWidth, (float)newHeight);
using (MemoryStream thumbStr = new MemoryStream())
{
thumb.Save(thumbStr, ImageFormat.Jpeg);
arr = thumbStr.ToArray();
}
g.Dispose();
img.Dispose();
return arr;
}
Most of the time it works great but sometimes it gives me this exception:A generic error occurred in GDI+. Error Code -2147467259. Source: "System.Drawing". This occurs on the Image.Save(... I tried to make this code as defensive as possible but am still not getting whats causing this. If someone knows the answer that'd be great, critiques are welcome too.
I personally use this code, with no streams (I don't care about perfs, though) for resizing a picture:
public Image resizeImage(int newWidth, int newHeight, string stPhotoPath)
{
Image imgPhoto = Image.FromFile(stPhotoPath);
int sourceWidth = imgPhoto.Width;
int sourceHeight = imgPhoto.Height;
//Consider vertical pics
if (sourceWidth < sourceHeight)
{
int buff = newWidth;
newWidth = newHeight;
newHeight = buff;
}
int sourceX = 0, sourceY = 0, destX = 0, destY = 0;
float nPercent = 0, nPercentW = 0, nPercentH = 0;
nPercentW = ((float)newWidth / (float)sourceWidth);
nPercentH = ((float)newHeight / (float)sourceHeight);
if (nPercentH < nPercentW)
{
nPercent = nPercentH;
destX = System.Convert.ToInt16((newWidth -
(sourceWidth * nPercent)) / 2);
}
else
{
nPercent = nPercentW;
destY = System.Convert.ToInt16((newHeight -
(sourceHeight * nPercent)) / 2);
}
int destWidth = (int)(sourceWidth * nPercent);
int destHeight = (int)(sourceHeight * nPercent);
Bitmap bmPhoto = new Bitmap(newWidth, newHeight,
PixelFormat.Format24bppRgb);
bmPhoto.SetResolution(imgPhoto.HorizontalResolution,
imgPhoto.VerticalResolution);
Graphics grPhoto = Graphics.FromImage(bmPhoto);
grPhoto.Clear(Color.Black);
grPhoto.InterpolationMode =
InterpolationMode.HighQualityBicubic;
grPhoto.DrawImage(imgPhoto,
new Rectangle(destX, destY, destWidth, destHeight),
new Rectangle(sourceX, sourceY, sourceWidth, sourceHeight),
GraphicsUnit.Pixel);
grPhoto.Dispose();
return bmPhoto;
}
Hope this helps.
Look at the documentation for Image.FromStream()
http://msdn.microsoft.com/en-us/library/93z9ee4x.aspx
You need to keep the stream open for the lifetime of the Image. Keep the first MemoryStream open longer, and it should work.
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With